Consequences of one-lung flooding: a histological and immunological investigation.
BACKGROUND
Videothoracoscopic lung sonography after partial fluid instillation could be a new method for endoscopic detection of lung lesions. Histopathological consequences of unilateral diagnostic or therapeutic lung flooding under bronchoalveolar lavage has yet to be defined. The aim of the study was to investigate histological and immunohistological alterations induced by one-lung flooding (OLF).


METHODS
13 female pigs were subjected to OLF (15 ml isotonic electrolyte solution per kg for 60 minutes), and lung tissue was collected 30 minutes, 2 hours, 24 hours, 48 hours, 6 days, 8 days, and 10 weeks after flooding. Histological examinations and immunohistochemical labeling for surfactant protein A (SP-A) were performed. Cellular proliferation was measured by Ki67 immunohistochemical labeling. Apoptosis was detected through enzymatic in-situ labeling of apoptosis-induced DNA strand breaks by means of the TUNEL (TdT-mediated dUTP nick end labeling) method.


RESULTS
Histological analyses revealed the presence of inflammatory cell infiltrates in the interstitium at 24 hours after OLF. However, no destruction of the alveolar wall and no pulmonary oedema were observed. In addition, OLF was not associated with any decrease in surfactant protein A immunoreactivity. Two hours after OLF, the number of apoptotic cells was increased (OLF: 7% vs.


METHODS
0.6%, p < 0.05), but cellular proliferation was unchanged. Conversely, at 48 h after OLF, the number of apoptotic cells had returned to control levels, but cellular proliferation had increased (OLF: 5% vs.


METHODS
1.1%, p < 0.05). Cellular proliferation returned to baseline levels eight days after OLF.


CONCLUSIONS
These data demonstrate that OLF is not associated with destruction of the alveolar texture, atelectasis-provoking surfactant loss, or any irreversible damage to the pulmonary parenchyma. Lung flooding for the purpose of videothoracoscopic lung sonography is safe and justifiable. But repeated lung flooding under bronchoalveolar lavage involving the same lung area within 1 week is not to be recommended.
Lesser
T
T
Department of Thoracic and Vascular Surgery, SRH Wald-Klinikum, Gera, Germany. thomas.lesser@wkg.srh.de
Klinzing
S
S
Schubert
H
H
Kosmehl
H
H
D000818:Animals; D017209:Apoptosis; D018893:Bronchoalveolar Lavage / Q000009:adverse effects*; D049109:Cell Proliferation; D004249:DNA Damage; D004195:Disease Models, Animal; D005260:Female; D007249:Inflammation / Q000473:pathology; D019394:Ki-67 Antigen / Q000378:metabolism; D008168:Lung / Q000378:metabolism / Q000473:pathology*; D011183:Postoperative Complications / Q000473:pathology* / Q000503:physiopathology; D011650:Pulmonary Alveoli / Q000378:metabolism / Q000473:pathology; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism; D013552:Swine; D013906:Thoracoscopy / Q000379:methods
D019394:Ki-67 Antigen; D037662:Pulmonary Surfactant-Associated Protein A